Image reading apparatus

ABSTRACT

An image reading apparatus which enables the area occupied by the apparatus to be made small and can stably transport even a thick sheet having stiffness. A sheet P contained in an inclined sheet containing portion  3  is transported to image reading portions  8  and  9  by a vertically extending first sheet transporting path R 1,  and an image on the sheet P is read by the image reading portions  8  and  9,  and the sheet P on which the image has been read is delivered to a substantially horizontal delivery stacking portion  14  by a substantially horizontally extending second sheet transporting path R 2.  The image reading portion  9  is provided between the vertically extending first sheet transporting path R 1  and the substantially horizontally extending second sheet transporting path R 2,  and in the image reading portion  9,  the transport direction of the sheet P passed along the first sheet transporting path R 1  is changed to a direction toward the second sheet transporting path R 2.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to an image reading apparatus, andparticularly to an image reading apparatus adapted to read an imageformed on a sheet while transporting the sheet.

[0003] 2. Related Background Art

[0004] As an image reading apparatus for reading an image formed on asheet, there is, for example, one of an original transporting type whichis adapted to read an image formed on an original which is a sheet whiletransporting the original. As such image reading apparatuses of theoriginal transporting type, there are known facsimile apparatuses,scanners, copying machines, etc.

[0005] Now, among these apparatuses, there is one of a type which readsthe images of the front side and back side of an original at a time.FIG. 12 of the accompanying drawings shows an example of such an imagereading apparatus according to the conventional art, and this imagereading apparatus is provided with a transport path for U-turning anoriginal P, i.e., a so-called U-turn path, in order to make the areaoccupied by the apparatus small.

[0006] When originals P are to be read, the originals P are first setwith their front sides facing upwardly on an original feed tray 401 onthe front face (the right side as viewed in FIG. 12) of the apparatus,and the uppermost one of the thus set originals P is separated by aseparation portion 402, and is fed into image reading portions 404 and405 by a pair of transport rollers 403.

[0007] Next, the images on the front side and back side of this originalP are read by image sensors 404 a and 405 a, respectively, provided inthe image reading portions 404 and 405. Platen rollers 404 b and 405 bare disposed in opposed relationship with these image sensors 404 a and405 a, respectively, and the original P is brought into close contactwith contact glass surfaces on the respective image sensors by theseplaten rollers 404 b and 405 b, whereby the reading of the images of theoriginal can be done well.

[0008] The original P of which the images on the front side and backside have been read in the this manner is thereafter passed through aU-turn guide portion 407 by a pair of transport rollers 406, and isstacked with its front side facing downwardly on an original deliverytray 409 provided on the upper surface of the apparatus, by a pair ofdelivery rollers 408.

[0009] According to the image reading apparatus of such a construction,the area occupied by the apparatus becomes relatively small andmoreover, the take-in and delivery of the original P are in the samedirection and therefore, the setting and collection of the originals Pcan be effected easily.

[0010] On the other hand, FIG. 13 of the accompanying drawings showsanother example of the image reading apparatus according to theconventional art, and this image reading apparatus is of a type in whichoriginals P are set on the upper portion of the rear side (the rightupper side as viewed in FIG. 13) of the apparatus with their front sidesfacing downward, and are transported substantially linearly.

[0011] When the originals P are to be read, the originals P are firstset on an original feed tray 401 with their front sides facing downward,and the uppermost one of the thus set originals P is separated by aseparation portion 402, and thereafter is fed into image readingportions 404 and 405 by a pair of transport rollers 403.

[0012] Next, the images on the front side and back side of this originalP are read by image sensors 404 a and 405 a provided in the imagereading portions 404 and 405, respectively. Thereafter, the original Pof which the images on the front side and back side have been thus readis stacked on an original delivery tray 409 in the lower portion of thefront side (the left lower side as viewed in FIG. 13) of the apparatuswith its front side facing downward by a pair of delivery rollers 408.

[0013] According to the image reading apparatus of such a construction,the transport path of the original P is a so-called straight pathapproximate to a straight line and therefore, there is the advantagethat relatively stable transport of the original P can be effected andmoreover, the transport rollers and the transport guides can be madeinto a necessary minimum construction. Further, if the angle of thestraight path is made great with respect to a horizontal plane and theangle of the original feed tray 401 is made upright and the original Pis transported at an angle approximate to verticality, the area occupied(projected) by the entire apparatus can be made small.

[0014] However, in such an image reading apparatus according to theconventional art, for example, in the image reading apparatus as shownin FIG. 12, to make the entire apparatus compact, it is necessary tomake the curvature of the U-turn guide portion small, but if thecurvature is made small, not only it will become impossible to transporta thick original having stiffness, but also the accuracy of transportwill be reduced and bad transport will become liable to occur.

[0015] That is, when an original is transported by the use of a U-turnpath small in curvature, the entire apparatus can be made compact, butthere is the disadvantage that as compared with the straight path, therange of application to the thickness of the original becomes narrow.There is also the disadvantage that transport rollers and a transportguide become necessary in the U-turn portion and the constructionbecomes complicated.

[0016] On the other hand, in the image reading apparatus as shown inFIG. 13, if the angle of the straight path is made great with respect tothe horizontal plane and the original is transported at an angleapproximate to verticality, the area occupied (projected) by theapparatus can be made small, but in this case, it is necessary todispose the original delivery tray 409 at an angle approximate toverticality.

[0017] However, if the original delivery tray 409 is disposed at anangle approximate to verticality as described above, there is thedisadvantage that the position of the original delivery tray 409 becomeshigh relative to the installation surface and the height dimension ofthe apparatus becomes great and the operability of the apparatus becomesbad. Accordingly, it is more advantageous in the compactness andoperability of the apparatus for the original delivery tray 409 to bedisposed at an angle as approximate to horizontal as possible.

[0018] However, if the original delivery tray 409 is disposed at anangle approximate to horizontal as described above, the transportdirection of the original P transported at an angle approximate toverticality will come to change greatly short of the original deliverytray 409. If the original delivery angle changes greatly like this,there has been the disadvantage that it becomes impossible to deliver athick original having stiffness or the delivered original becomes bentor delivery jam becomes liable to occur.

[0019] Also, in recent years, an image forming apparatus such as animage reading apparatus, a printer, a copying machine or a facsimileapparatus is provided with a sheet feeding apparatus for separatingsheets one by one and feeding them to an image reading portion or animage forming portion. As such a sheet feeding apparatus, use is widelymade of one adopting a retard separation type capable of separatingsheets with high reliability from a low speed to a high speed, as amechanism for separating the sheets.

[0020] As shown, for example, in FIGS. 14A, 14B and 14C of theaccompanying drawings, the retard separation type is adapted to separateand feed sheets S one by one by a feed roller 411 rotated in a sheetfeeding direction (the direction indicated by the arrow A in FIG. 14A),and a separation roller 412 (retard roller) urged against the feedroller 411 with predetermined pressure and rotated in a directionopposite to the sheet feeding direction, in other words, a direction forreturning the sheets S.

[0021] A torque limiter for generating slide at a prescribed or greaterload is provided in the driving force transmitting path of theseparation roller 412. This torque limiter is usually adapted to work bya load comprising the frictional force between the feed roller 411 andthe sheet S. Thereby, the separation roller 412 is adapted to follow therotation of (be rotated with) the sheet S, and transport a sheet.

[0022] On the other hand, when a plurality of sheets S overlapping oneanother come into the nip between the rollers, a sheet S which isbrought into contact with the feed roller 411 by the slide among thesheets S is transported in the feeding direction. A sheet which is incontact with the separation roller 412 side is adapted to be returned bythe separation roller 412 being reversely rotated.

[0023] Further, when multiple sheets S superposed one upon another areset, the stack of the sheets dashes into the nip between the rollers andthe double feed of multiple sheets occurs. In order to prevent it, thereis also known an apparatus in which as shown in FIG. 14B, an inclinedsurface portion is formed on this side of the separation roller 412 oras shown in FIG. 14C, a wall portion is formed to thereby provide such aguide portion 420 that a stack of a predetermined number of or moresheets does not dash into the nip.

[0024] However, in the above-described examples of the conventional art,particularly in the case of a longitudinal type sheet feeding mechanism,a stack of multiple sheets superposed one upon another is directlyplaced in the roller nip portion of the transport and separation deviceand therefore, the above-described operation of the separation roller412 is blocked to thereby cause double feed and bad feed. Also, even ifthe guide portion 420 shown in FIG. 14B or 14C is provided, sheetshaving a high coefficient of friction come into between the guideportion 420 and a transport guide more than necessary, with the aid ofgravity of the sheets S, to thereby cause the double feed of multiplesheets or the non-feed by sheet jam.

SUMMARY OF THE INVENTION

[0025] So, the present invention has been made of such circumstances andan object thereof is to provide an image reading apparatus which can bemade small in the area occupied (projected) by the apparatus and canstably transport even a thick original (sheet) having stiffness.

[0026] Another object of the present invention is to provide a sheettransporting and separating apparatus which even if multiple sheets areset, can reliable separate them into a sheet and transport it, andeliminate the situation in which the treatment of the sheets has beenstagnated by non-feed.

[0027] The present invention provides an image reading apparatus adaptedto read an image on a sheet contained in an inclined sheet containingportion, and thereafter deliver the sheet, and provided with an imagereading portion for reading the image on the sheet, a substantiallyhorizontal delivery stacking portion for stacking the delivered sheetthereon, a vertically extending first sheet transporting path fortransporting the sheet to the image reading portion, and a substantiallyhorizontally extending second sheet transporting path for transportingthe sheet on which the image has been read to the substantiallyhorizontal delivery stacking portion, the image reading portion beingprovided between the vertically extending first sheet transporting pathand the horizontally extending second sheet transporting path, and thetransport direction of the sheet passed along the first sheettransporting path being changed to a direction toward the second sheettransporting path in the image reading portion.

[0028] Also, in the present invention, the image reading portion may beprovided in a state horizontally inclined more by a predetermined amountthan the angle of the first sheet transporting path, and the transportdirection of the sheet may be changed on a surface containing thereading position of the image reading portion.

[0029] Also, in the present invention, the image reading portion may beprovided with image reading means for reading the image on the sheet,and regulating means provided in opposed relationship with the imagereading means for causing the sheet to pass while bringing the sheetinto close contact with the image reading means.

[0030] Also in the present invention, the regulating means maypreferably be a roller.

[0031] Also, in the present invention, the roller may be provided whilebeing deviated by a predetermined distance toward the upstream side ofthe reading position of the image reading means in the transportdirection of the sheet.

[0032] Also, in the present invention, the regulating means may be aplate-shaped member having a smooth surface, and the plate-shaped membermay be provided at a predetermined position upstream of the readingposition of the image reading means in the transport direction of thesheet and whereat the transport direction of the sheet can be changed.

[0033] Also, the present invention provides an image reading apparatusprovided with original transporting means for transporting an originalalong a transporting path, image reading means for reading the imageinformation of the original transported by the original transportingmeans at a predetermined reading position, and original delivering meansfor delivering the original read by the image reading means, wherein thetransporting path is bent near the reading position of the image readingmeans.

[0034] Also, in the present invention, the transporting path maypreferably be bent upstream of the image reading position of the imagereading means.

[0035] Also, in the present invention, the image reading apparatus maybe provided with regulating means provided in opposed relationship withthe image reading means for causing the original to pass while bringingthe original into close contact with the original reading surface of theimage reading means, and the transporting path may preferably be bentalong the regulating means.

[0036] Also, in the present invention, the regulating means may includea roller, and the transporting path may preferably be bent along theperipheral surface of the roller.

[0037] Also, in the present invention, the regulating means maypreferably be provided with a predetermined amount of deviation towardthe upstream side of the reading position of the image reading means inthe transport direction of the original.

[0038] Also, in the present invention, the shaft center position of theroller may preferably be disposed with a predetermined amount ofdeviation toward the upstream side of the reading position of theoriginal reading surface in the transport direction of the original.

[0039] Also, the sheet transporting and separating apparatus of thepresent invention is a sheet transporting and separating apparatus forseparating a plurality of sheets into one sheet and transporting it by apair of rollers comprising a feed roller and a separation rollerdisposed in opposed relationship with each other, the separation rolleris comprised of an elastic member, and a transport regulating guideadapted to be relatively protruded by the deformation of the elasticmember is provided near the separation roller.

[0040] Also, in the sheet transporting and separating apparatus of thepresent invention, the transporting regulating guide may preferably beformed so that as it becomes closer to the nip portion between the pairof rollers, the amount of deformation of the separation roller requiredto protrude may increase.

[0041] Also, in the sheet transporting and separating apparatus of thepresent invention, the transport regulating guide may preferably beformed into the shape of a staircase.

[0042] Also, in the sheet transporting and separating apparatus of thepresent invention, the transport regulating guide may preferably beformed of a flexible material, and may about against the vicinity of thenip portion between the pair of rollers on the feed roller.

[0043] Also, in the sheet transporting and separating apparatus of thepresent invention, the transport regulating guide may preferably beformed of an elastically deformable flexible material, and may bedesigned to come into the feed roller side in non-contact therewith soas to interrupt the transport of the sheet near the nip portion betweenthe pair of rollers on the feed roller.

[0044] Also, in the sheet transporting and separating apparatus of thepresent invention, an uneven shape may preferably be formed on that sideof the transport regulating guide which is adjacent to the feed roller.

[0045] According to the present invention, by the above-describedconstruction, even if a sheet stack comprising multiple sheetssuperposed one upon another dashes in, it becomes possible to receivethe sheet stack by the transport regulating guide having the sheetreceiving function without hindering the operation of the separationroller, and suppress the entry of the sheets to the entry of a propersmall number of sheets into the nip between the pair of rollers. Also,even if a sheet is caught by the transport regulating guide, theseparation roller comprising an elastic member pushes out the sheet andtherefore, the non-feed of the sheet can be avoided.

[0046] Also, even with the transport regulating guide made to abutagainst the feed roller or enter in the non-contact therewith it becomespossible to suppress the entry of a stack of multiple sheets superposedone upon another to the entry of a proper small number of sheets, andhandle the leading edge portion of the sheets by the uneven shapethereof and reliably separate them into one sheet.

BRIEF DESCRIPTION OF THE DRAWINGS

[0047]FIG. 1 is a pictorial perspective view of an image readingapparatus according to a first embodiment of the present invention.

[0048]FIG. 2 is a cross-sectional view schematically showing theconstruction of the image reading apparatus of FIG. 1.

[0049]FIG. 3 is a cross-sectional view showing the construction of thecontact image sensor of an image reading portion provided in the imagereading apparatus of FIG. 1.

[0050]FIG. 4 is a cross-sectional view showing a state in which firstand second transporting paths of the image reading apparatus of FIG. 1are opened.

[0051]FIG. 5 shows the original transport driving system of the imagereading apparatus of FIG. 1.

[0052]FIG. 6 is an enlarged view of the essential portions of an imagereading apparatus according to a second embodiment of the presentinvention.

[0053]FIG. 7 is an enlarged view of the essential portions of an imagereading apparatus according to a third embodiment of the presentinvention.

[0054]FIG. 8A shows the construction of the essential portions of asheet transporting and separating apparatus in a fourth embodiment ofthe present invention. FIG. 8B is an enlarged view of the encircledportion indicated by the circle of VIIIB in FIG. 8A.

[0055]FIGS. 9A and 9B show an image reading apparatus according to anembodiment of the present invention.

[0056]FIGS. 10A and 10B show a sheet transporting and separatingapparatus in another embodiment of the present invention. FIG. 10C is anenlarged view of the encircled portion indicated by the circle of XC inFIG. 10A.

[0057]FIG. 11 is a perspective view showing a sheet transporting andseparating apparatus in still another embodiment of the presentinvention.

[0058]FIG. 12 schematically shows the construction of an example of animage reading apparatus according to the conventional art

[0059]FIG. 13 schematically shows the construction of another example ofthe image reading apparatus according to the conventional art.

[0060]FIGS. 14A, 14B and 14C show the construction of a sheettransporting and separating apparatus according to the conventional art.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0061] Some embodiments of the present invention will hereinafter bedescribed in detail with reference to the drawings.

[0062]FIG. 1 is a pictorial perspective view of an image readingapparatus according to a first embodiment of the present invention, andFIG. 2 is a cross-sectional view schematically showing the constructionthereof.

[0063] In FIGS. 1 and 2, the reference numeral 1 designates the imagereading apparatus, the reference character 1A denotes the main body ofthe image reading apparatus (hereinafter referred to as the main body ofthe apparatus), the reference numeral 2 designates a feed port providedin the upper portion of the main body 1A of the apparatus, and thereference numeral 3 denotes an original feed tray which is an inclinedsheet containing portion disposed above the feed port 2 at an angleapproximate to vertically, and an original P which is a sheet is set onthe original feed tray 3 with its lower end portion inserted in the feedport 2 and with its front side facing downward.

[0064] Also, the reference numeral 5 designates a feed roller given adriving force in a direction for pulling the original P into the mainbody 1A of the apparatus, and the reference numeral 6 denotes a retardroller which is adapted to be given a driving force in a direction forpushing back the original P with predetermined torque by a torquelimiter 30 shown in FIG. 5 to be described later which is connected tothe retard roller 6.

[0065] Also, the reference numerals 8 and 9 designate upper and lowerimage reading portions for reading the images of the original P, andthese upper and lower image reading portions 8 and 9 are disposed with afirst transporting path R1 which will be described later interposedtherebetween, and design is made such that the image on the back side ofthe original P is read by the upper image reading portion 8 and theimage on the front side of the original P is read by the lower imagereading portion 9.

[0066] Description will now be made of the image reading operation ofthe thus constructed image reading apparatus 1.

[0067] When the start button 4 of an operating portion shown in FIG. 1is first depressed and a reading start command is outputted, the feedroller 5 and the retard roller 6 start to be rotated. When only anoriginal P has entered the nip portion between the feed roller 5 and theretard roller 6, the retard roller 6 is rotated with the original P bythe torque limiter, whereby the original P is fed to transport rollers 7by the transporting force of the feed roller 5.

[0068] Also, when a plurality of originals P have entered the nipportion at a time, the retard roller 6 is rotated in a directionopposite to the transport direction of the originals P by the torquelimiter to thereby push back the second and subsequent originals P whichare out of contact with the feed roller 5, and when the first original Palone remains, the retard roller 6 starts to be rotated with thatoriginal P in accordance with the transport thereof. By such retardseparation by the retard roller 6, the originals P are separated one byone and fed to the transport rollers 7.

[0069] Next, the original P is transported to the upper and lower imagereading portions 8 and 9 at a predetermined speed by the transportrollers 7. Now, in the present embodiment, these upper and lower imagereading portions 8 and 9 are adapted to read the images formed on thefront side and back side of the originals P by contact image sensors 200which are image reading means.

[0070]FIG. 3 shows the construction of such a contact image sensor 200,and as shown in FIG. 3, the contact image sensor 200 has an LED 202which is a light source, a lens array 203 and an image sensor (lightreceiving element) 204 disposed in a frame 201, and contact glass 205 isinstalled on the upper surface of the frame 201 including the readingposition A of the contact image sensor 200.

[0071] The contact image sensor 200 is designed such that when theoriginal P passes the upper portion of the contact glass 205, light isprojected thereto by the LED 202. The thus projected light is reflectedby the original reading surface of the reading position A, and is imagedon the image sensor (light receiving element) 204 by the lens array 203.The thus imaged image is converted into an electrical signal by theimage sensor (light receiving element) 204, whereafter various kinds ofimage processing are effected, whereby the images of the original areread.

[0072] This contact image sensor 200 is shallow in depth of focus andtherefore, in the upper and lower image reading portions 8 and 9provided with such contact image sensors 200, to read the imageinformation of the original P well, it is necessary to bring theoriginal P into close contact with the surface of the contact glassinstalled on the contact image sensors.

[0073] Therefore, as shown in FIG. 2, in opposed relationship with thereading positions A of the upper and lower image reading portions 8 and9, there are installed platen rollers 10 and 11 which are regulatingmeans for pressing the original P into close contact with the originalreading surfaces of the image reading portions 8 and 9 (the surfaces ofthe contact glass shown in FIG. 3) and also transporting the original Pat a predetermined speed.

[0074] In the present invention, the surfaces of these platen rollers 10and 11 are white so as to be capable of effecting the detection of ashading signal. The detection of the shading signal is effected byreading the white reference level of the white surfaces of the platenrollers 10 and 11 by the contact image sensors 200 before the original Pis transported to the image reading portions 8 and 9.

[0075] Further, in the present embodiment, the platen rollers 10 and 11are held so that the outer peripheral surfaces thereof may not directlycontact with but keep a predetermined interval (of the order of 0.5 mm)relative to the original reading surfaces of the upper and lower imagereading portions 8 and 9 (the surfaces of the contact glass).

[0076] This is for preventing the occurrence of the stains and scars ofthe white surfaces of the platen rollers 10 and 11, and preventing thebad detection of the shading signal and at the same time, suppressingthe load of a mechanical system from being increased by the contactfriction between the platen rollers 10, 11 and the contact glass whenthe original P is absent.

[0077] On the other hand, as already described, the original P which haspassed the transport rollers 7 has the image on its back side read inthe upper image reading portion 8 having its reading surface disposed inparallelism to the transport direction of the original, whereafter ithas the image on its front side read in the lower image reading portion9.

[0078] Next, the original P which has passed the reading position A ofthis lower image reading portion 9 is transported to delivery rollers 12which are original delivering means and is delivered from a deliveryport 13 onto an original delivery tray 14 which is a substantiallyhorizontal delivery stacking portion with its front side facing downwardby the delivery rollers 12. The second and subsequent originals P arealso subjected to a similar operation, and the originals P are stackedon the original delivery tray 14 in the same order as when they were seton the original feed tray 3.

[0079] Now, the original P is transported at a constant speed by thetransport rollers 7, the platen rollers 10, 11 and the delivery rollers12 until the trailing edge of the original P completely passes betweenthe delivery rollers 12. The original feeding speed of the feed roller 5is set to a speed lower than that of the rollers 7, 10, 11 and 12 sothat the reading of the images of the original may be effectedappropriately.

[0080] Even when as described above, the original feeding speed of thefeed roller 5 is set to a speed lower than the original transportingspeed of the rollers 7, 10, 11 and 12, the feed roller 5 is adapted tobe rotated with the original P from after the leading edge portion ofthe original P has arrived at the transport rollers 7 until the trailingedge portion of the original P passes the feed roller 5, because aone-way clutch (not shown) is connected to the roller driving shaft ofthe feed roller 5.

[0081] On the other hand, in FIG. 2, the reference numeral 16 designatesa lower frame provided with the feed roller 5, the transport (drive)rollers 7, the platen roller 10, the lower image reading portion 9 andthe delivery (drive) roller 12 and forming a lower transport guide, andthe reference numeral 17 denotes an upper frame provided with the retardroller 6, the transport (driven) roller 7, the upper image readingportion 8, the platen roller 12 and the delivery (driven) roller 12 andforming an upper transport guide.

[0082] A first transporting path R1 which is a vertically extendingfirst sheet transporting path for transporting the original P to theimage reading portions 8 and 9, and a second transporting path R2 whichis a second sheet transporting path for transporting the original P ofwhich the images have been read to a substantially horizontal originaldelivery tray 14 are formed by the lower frame 16 and the upper frame17.

[0083] The upper frame 17, as shown in FIG. 4, is supported on the mainbody 1A of the apparatus for pivotal movement with an opening andclosing hinge 15 provided near the delivery roller 12 as a fulcrum. Whenthe original P is jammed on the transporting path or when the contactglass and the platen rollers 10 and 11 of the image reading portions 8and 9 are stained, the upper frame 17 is pivotally moved with theopening and closing hinge 15 as the fulcrum as shown in FIG. 4 tothereby open the first and second transporting paths R1 and R2, wherebythe treatment of the jam of the original or the cleaning of the contactglass 205 and the platen rollers 10 and 11 can be done easily.

[0084] On the other hand, FIG. 5 shows the original transport drivingsystem of the image reading apparatus 1 according to the presentembodiment. In FIG. 5, the reference numeral 18 denotes an originaltransporting motor, and the motor gear 19 of this original transportingmotor 18 is connected to a gear 20 fixed to the shaft 12 a of thedelivery (drive) roller 12, gears 22 and 21 fixed to the shafts 10 a and11 a, respectively, of the platen rollers 10 and 11, a gear 23 fixed tothe shaft 7 a of the transport (drive) roller 7, and a gear 24 fixed tothe shaft 5 a of the feed roller 5, by a gear train 19A, so as totransmit the drive of the motor to the rollers 7, 10, 11 and 12.

[0085] The drive of the gear 24 fixed to the shaft 5 a of the feedroller 5 is adapted to be further transmitted by gears 25, 26, pulleys27, 28 and a belt 29 so as to drive the retard roller 6 through a torquelimiter 30 mounted in the retard roller 6.

[0086] Now, in the present embodiment, the lower image reading portion9, as shown in FIG. 2, is provided in a state in which the readingsurface thereof is inclined in a horizontal direction by a predeterminedangle with respect to the original transport direction up to the upperimage reading portion 8 provided upstream, in other words, with respectto the sheet transport direction (angle) in the first transporting pathR1.

[0087] By the lower image reading portion 9 being thus provided in astate in which it is inclined by the predetermined angle, the original Pwhich has passed the reading position A in the lower image readingportion 9 is adapted to be transported to the second transporting pathR2 while changing its transport direction along the surface of thecontact glass 205 including the reading position A by the platen roller11.

[0088] By the original P being thus transported while changing itstransport direction by the platen roller 11, even when the angle formedby the first transporting path R1 with the second transporting path R2is great, the transport direction of the original P can be changedwithin a short transport distance range and without the use of anydiscrete roller or the like.

[0089] As a result, the delivery of the original to the originaldelivery tray 14 can be effected smoothly even when the original feedtray 3 is provided at an angle approximate to verticality and theoriginal delivery tray 14 is disposed at an angle approximate tohorizontal. Also, the entire original transporting path can be madecompact, whereby the main body 1A of the apparatus can be downsized andthe area occupied (projected) by the apparatus can be made small.Further, even a thick original P having stiffness can be stablytransported.

[0090] Now, when the leading edge portion of the original P passes thereading positions A of the image reading portions 8 and 9, if the shaftcenter positions of the platen rollers 10 and 11 coincide with thereading positions A of the contact image sensors 200 of the imagereading portions 8 and 9 on the surface opposed to the platen rollers 10and 11, the original P may be fluttered between the contact imagesensors 200 and the platen rollers 10, 11 by the shock when the leadingedge portion of the original P being transported comes into contact withthe platen rollers 10, 11 or the surfaces of the contact glass of thecontact image sensors 200 and therefore, it is preferable in effectingappropriate image reading to suppress such fluttering of the original P.

[0091] Description will now be made of a second embodiment of thepresent invention in which such fluttering of the original P issuppressed.

[0092]FIG. 6 is an enlarged view of the essential portions of an imagereading apparatus according to the present embodiment. In FIG. 6, thesame reference characters as those in FIG. 2 designate the same orcorresponding portions.

[0093] In the present embodiment, as shown in FIG. 6, the shaft centerpositions of the platen rollers 10 and 11 are disposed at locationsdeviated by a predetermined amount δ from the reading positions A of thecontact image sensors 200 of the image reading portions 8 and 9 towardthe upstream side in the original transport direction.

[0094] By the shaft center positions of the platen rollers 10 and 11being thus disposed on the upstream side (this side) of the readingpositions A of the contact image sensors 200, when the original Pcontacts with the platen rollers 10 and 11 or the surfaces of thecontact glass of the contact image sensors 200, the then shock can beprevented from affecting the read image and also, the behavior of theleading edge portion of the original at the reading positions A can bestabilized.

[0095] In the present embodiment, the value of this amount of deviationδ is of the order of 0.5 to 1.5 mm relative to the diameter 12 mm of theplaten rollers. However, even such a slight amount of deviation δ canachieve a sufficient effect because the image reading line width of thecontact image sensors 200 is very minute.

[0096] By the shaft center positions of the platen rollers 10 and 11being thus deviated by the predetermined amount δ from the readingpositions of the contact image sensors 200 toward the upstream side inthe original transport direction, the fluttering of the original P whenthe leading edge portion thereof passes the reading positions A can besuppressed to thereby prevent the inconveniences of an image such as theblur and density unevenness of the read image.

[0097] Now, while in the description hitherto made, there has beendescribed a case where in order to bring the original P into closecontact with the original reading surface, the platen rollers 10 and 11are disposed in opposed relationship with the reading positions A of thecontact image sensors 200, the present invention is not restrictedthereto, but design may also be made such that the original P is broughtinto close contact with the contact image sensors 200 by other member.

[0098] Description will now be made of a third embodiment of the presentinvention in which as described above, the original P is brought intoclose contact with the contact image sensors 200 by the use of othermember.

[0099]FIG. 7 is an enlarged view of the essential portions of an imagereading apparatus according to the present embodiment. In FIG. 7, thesame reference characters as those in FIG. 2 designate the same orcorresponding portions.

[0100] In FIG. 7, the reference numerals 31 and 32 denote sheet memberswhich are plate-shaped members provided, instead of the platen rollers,in opposed relationship with the contact image sensors 200 of the upperand lower image reading portions 8 and 9. These sheet members 31 and 32are fixed with a predetermined interval kept with respect to thesurfaces of the contact glass of the contact image sensors 200 so thatthe sheet members 31 and 32 as regulating means can bring the original Pinto close contact with the contact image sensors 200.

[0101] Again in the present embodiment, as in the aforedescribed firstand second embodiments, the lower image reading portion 9 is provided atsuch a position that the transport angle of the original P is changed bythe lower image reading portion 9, and the sheet members 31 and 32 areprovided at such positions that the transport angle of the original P ischanged on a surface containing the reading position of the lower imagereading portion 9.

[0102] Further, the surfaces of the sheet members 31 and 32 are smoothlyformed, and by the surfaces being thus made smooth, the transportresistance of the original P can be minimized and the transport jamthereof can be prevented. Further, by the color of the sheet members 31and 32 being made white, they can be endowed with the function as whitereference plates and can effect the detection of a shading signal.

[0103] As described above, design is made such that the original P isbrought into close contact with the original reading surfaces of theimage reading portions 8 and 9 by the sheet members 31 and 32, whereby adriving mechanism for driving the rollers as in the case where theplaten rollers are used becomes unnecessary. Thereby, the structure ofthe apparatus becomes simple and the cost thereof can be reduced.

[0104] While in the present embodiment, the sheet members 31 and 32 arefixed with a predetermined interval kept with respect to the surfaces ofthe contact glass of the contact image sensors 200, the sheet membersmay be brought into contact with the surfaces of the contact glass witha minute pressure force by pressing means such as pressing springs.

[0105] Also, the points at which the transport direction of the originalP is changed in the lower image reading portion 9 need not strictly bethe reading positions A, but may be any positions on the surfaces of thecontact glass 205 which are upstream of the reading positions A in thetransport direction.

[0106] Next, for further detailed description, in each of theabove-described embodiments, the contact image sensor 200 of the upperimage reading portion 8 will be referred to as the first image sensor 8a, and the contact image sensor 200 of the lower image reading portion 9will be referred to as the second image sensor 9 b (typically see FIG.6).

[0107] In the upper image reading portion 8, a first reading andtransporting path for guiding the sheet is formed by the first contactglass 8 c of the first image sensor 8 a

[0108] In the lower image reading portion 9, a second reading andtransporting path for guiding the sheet is formed by the second contactglass 9 c of the second image sensor 9 a.

[0109] The angle of inclination θ1 of the guide surface 8 b of the firstcontact glass 8 c with respect to the horizontal plane is greater thanthe angle of inclination θ2 of the guide surface 9 b of the secondcontact glass 9 c with respect to the horizontal plane.

[0110] The angle of inclination θ3 of the common tangent (sheet deliverydirection) of the pair of delivery rollers 12 with respect to thehorizontal plane is smaller than the angle of inclination θ2 of theguide surface 9 b of the second contact glass 9 c with respect to thehorizontal plane.

[0111] That is, the relation that

θ1>θ2>θ3

[0112] is satisfied.

[0113] A fourth embodiment of the present invention will hereinafter bedescribed with reference to the drawings. FIGS. 9A and 9B show theconstruction of an image reading apparatus which is an example of theapplication of the present invention. The epitome of this image readingapparatus will hereinafter be described. The reference numeral 300designates the image reading apparatus, the reference character 300Adenotes the main body of the image reading apparatus, the referencecharacter 300B designates a sheet stacking portion which is a sheetcontaining portion in which sheets S are stacked and contained, thereference numerals 302 and 303 denote front side and back side imagereading portions for reading the images on the sheets S, and thereference character 300C designates a sheet feeding apparatus forfeeding the sheets S contained in the sheet stacking portion 300B to thefront side and back side image reading portions 302 and 303.

[0114] The sheet feeding apparatus 300C is provided with separating andfeeding means comprised of a feed roller 311 which is a feed rotarymember and a separation roller 312 which is a separation rotary memberurged against the feed roller 311, and for separating the sheets Sstacked on the sheet stacking portion 300B one by one. The referencenumeral 313 denotes a main motor for driving the feed roller 311 and theseparation roller 312.

[0115] Description will now be made of the image reading operation ofthe thus constructed image reading apparatus 300. When the image readingoperation is started, the plurality of sheets S placed on the sheetstacking portion 300B are separated one by one by the feed roller 311and the separation roller 312 which are in pressure contact with eachother. Thereafter, the sheet is passed while being into close contactwith the front side and back side image reading portions 302 and 303 byplaten rollers 302 a and 303 a.

[0116] During this passage, the image formed on the front side or theback side of the sheet S is line-scanned by passing while facing thefront side and back side image reading portions 302 and 303, and isoutputted as an electrical signal to the outside. Also, after thereading of the image has been thus effected, the sheet S is delivered tothe outside by delivery rollers 304 (a pair of delivery rollers 304 aand 304 b).

[0117] In FIGS. 9A and 9B, the reference numeral 301 designates an upperunit constituting the main body of the sheet feeding apparatus providedwith the separation roller 312, the back side image reading portion 303,the upper delivery roller 304 a, etc. This upper unit 301 is usuallyclosed as shown in FIG. 9A, but for example, in case of jam treatment,the cleaning of the rollers, etc. and maintenance, it is adapted to beupwardly opened as shown in FIG. 9B with a sheet transporting path R asthe boundary. By being thus opened, it is designed to be capable ofspacing the separation roller 312 apart from the feed roller 311.

[0118] Referring now to FIGS. 8A and 8B which best represent the sheettransporting and separating apparatus of the present invention, theconstruction of the present invention will be described. The sheettransporting and separating apparatus of the present invention includesa feed roller 311 and a separation roller 312 opposed to and being inpressure contact with each other, and the feed roller 311 is rotated inthe sheet transport direction, and the separation roller 312 iscomprised of an elastic member and has motive power transmitted theretoso as to be rotated in the opposite direction.

[0119] Also, there is provided a torque limiter in the drivetransmitting path of the separation roller 312, and the separationroller is driven to rotate (is rotated with the sheet) in the sheettransporting direction in a state in which there is sheet S or a statein which a sheet is being transported between the feed roller 311 andthe separation roller 312. In a state in which a plurality of sheetssuperposed one upon another have dashed into between these rollers, theseparation roller 312 is designed to be rotated in the oppositedirection. Also, in the present construction, transport regulatingguides 314 are formed on the opposite sides of the separation roller 312so that sheets superposed one upon another beyond a prescribed number ofsheets may not dash into between the rollers.

[0120] These transport regulating guides 314, as shown in FIG. 8A, areformed inside the outer periphery of the separation roller 312, and thesurfaces thereof against which the sheets dash are formed in the shapeof a staircase so that the distance thereof from the outer periphery mayincrease, that is, may be x1>x2 as shown in FIG. 8B, as it approachesthe nip. Also, the surface opposed to the feed roller 311 is formed soas to have a gap y1 calculated from the number of separable sheets S.

[0121] By the present construction, the transport regulating guide 314is formed so as to protrude relative to the separation roller 312 so asto be exposed from the separation roller 312 when multiple sheets S highin coefficient of friction and liable to enter together have deformedthe separation roller 312 and have dashed in. Thereby, even if themultiple sheets S have dashed in, they are received by the staircaseshape of the transport regulating guide 314 and only separable sheetscorresponding to the gap y1 enter while overlapping one another, and canbe reliably separated to one sheet by the retard roller portion and betransported to an image processing portion.

[0122] Even when the sheet S is caught by the staircase-shaped portionof the transport regulating guide 314, the sheet S is kicked out by theseparation roller 312 comprised of an elastic member starting to berotated in the opposite direction and is fed into the nip between therollers, and can go out of a non-fed state. Thereby, even if multiplesheets S are set, they can be reliably separated into one sheet andtransported to thereby eliminate a situation in which the treatment ofthe sheets has been stagnated by non-feed.

[0123] Also, in another embodiment, as shown in FIGS. 10A, 10B and 10C,the transport regulating guide 314 is formed of an elasticallydeformable flexible material. As shown in FIG. 10A, the tip end portionof a transport regulating tongue plate 315 is made to abut against thefeed roller 311. In this case, a similar effect can also be obtained byforming the abutting surface into an uneven shape (grooves 315 a) asshown in FIG. 10C.

[0124] A similar effect can also be obtained by not making the transportregulating tongue plate 315 abut against the inside of the outerdiameter of the feed roller 311, but making it noncontact-enter the feedroller 311 side so as to interrupt the sheet transport, as shown in FIG.10B.

[0125] Further, if the transport regulating guide 314 and the transportregulating tongue plate 315 are used together, a better effect will beobtained.

[0126] As described above, according to the present invention, an imagereading portion is provided between a vertically extending first sheettransporting path for transporting sheets contained in an inclined sheetcontaining portion to the image reading portion and a substantiallyhorizontally extending second sheet transporting path for delivering thesheets on which the images have been read to a substantially horizontaldelivery stacking portion, and the transport direction of the sheethaving passed the first sheet transporting path is changed to adirection toward the second sheet transporting path by the image readingportion, whereby the area occupied by the apparatus can be made smalland even a thick sheet having stiffness can be transported stably.

[0127] As described above, according to the present invention, even ifmultiple sheets are set in the sheet transporting and separatingapparatus of this kind, they can be reliably separated into one sheetand transported, to thereby eliminate the situation in which thetreatment of the sheets has been stagnated by non-feed. Thereby, therecan be realized an apparatus which operates smoothly and is high inreliability.

What is claimed is:
 1. An image reading apparatus for reading an imageon a sheet contained in an inclined sheet containing portion, andthereafter delivering the sheet, said image reading apparatuscomprising: an image reading portion for reading the image on the sheet;a substantially horizontal delivery stacking portion for stacking thedelivered sheet thereon; a vertically extending first sheet transportingpath for transporting the sheet to said image reading portion; and asubstantially horizontally extending second sheet transporting path fortransporting the sheet on which the image has been read to saidsubstantially horizontal delivery stacking portion, wherein said imagereading portion is provided between said vertically extending firstsheet transporting path and said substantially horizontally extendingsecond sheet transporting path, and in said image reading portion, atransport direction of the sheet which has passed said first sheettransporting path is changed to a direction toward said second sheettransporting path.
 2. An image reading apparatus according to claim 1,wherein said image reading portion is provided in a state that saidimage reading portion is inclined at an angle more getting toward ahorizontal direction by a predetermined amount than an angle of saidfirst sheet transporting path, and the transport direction of the sheetis changed on a surface containing a reading position of said imagereading portion.
 3. An image reading apparatus according to claim 1 or2, wherein said image reading portion comprises image reading means forreading the image on the sheet, and regulating means opposed to saidimage reading means for causing the sheet to pass said image readingmeans while bringing the sheet into close contact with said imagereading means.
 4. An image reading apparatus according to claim 3,wherein said regulating means is a roller
 5. An image reading apparatusaccording to claim 4, wherein said roller is disposed upstream of thereading position of said image reading means by a predetermined distancein the transport direction of the sheet.
 6. An image reading apparatusaccording to claim 3, wherein said regulating means is a plate-shapedmember having a smooth surface, and said plate-shaped member is disposedin a predetermined position in which the transport direction of thesheet can be changed upstream of the reading position of said imagereading means in the transport direction of the sheet.
 7. An imagereading apparatus comprising: original transporting means fortransporting an original along a transporting path; image reading meansfor reading image information of the original transported by saidoriginal transporting means in a predetermined reading position; andoriginal delivering means for delivering the original read by said imagereading means, wherein said transporting path is bent in a vicinity ofthe predetermined reading position of said image reading means.
 8. Animage reading apparatus according to claim 7, wherein said transportingpath is bent upstream of the predetermined reading position of saidimage reading means.
 9. An image reading apparatus according to claim 7or 8, further comprising regulating means opposed to said image readingmeans for causing the original to pass said image reading means whilebringing the original into close contact with an original readingsurface of said image reading means, wherein said transporting path isbent along said regulating means.
 10. An image reading apparatusaccording to claim 9, wherein said regulating means includes a roller,and said transporting path is bent along a peripheral surface of saidroller.
 11. An image reading apparatus according to claim 9, whereinsaid regulating means is disposed upstream of the predetermined readingposition of said image reading means by a predetermined distance in atransport direction of the original.
 12. An image reading apparatusaccording to claim 10, wherein a shaft center position of said roller isdisposed upstream of the predetermined reading position of said imagereading means by a predetermined distance in a transport direction ofthe original.
 13. A sheet transporting and separating apparatus forseparating a plurality of sheets into a sheet by a pair of rollerscomprising a feed roller and a separation roller opposed to said feedroller and transporting the sheet, wherein said separation rollercomprises an elastic member, and a transport regulating guide adapted tobe relatively protruded by a deformation of the elastic member isprovided in a vicinity of said separation roller.
 14. A sheettransporting and separating apparatus according to claim 13, whereinsaid transport regulating guide is formed so that an amount ofdeformation of said separation roller required to protrude saidtransport regulating guide increases as it approaches a nip portionbetween said pair of rollers.
 15. A sheet transporting and separatingapparatus according to claim 13 or 14, wherein said transport regulatingguide is formed into a shape of a staircase.
 16. A sheet transportingand separating apparatus according to claim 13 or 14, wherein saidtransport regulating guide is formed of a flexible material, and abutsagainst said feed roller in a vicinity of a nip portion between saidpair of rollers.
 17. A sheet transporting and separating apparatusaccording to claim 16, wherein said transport regulating guide is formedof the flexible material which is elastically deformable, and enters aside of said feed roller out of contact with said feed roller tointerrupt a transport of the sheet in the vicinity of the nip portionbetween the pair of rollers.
 18. A sheet transporting and separatingapparatus according to claim 16, wherein an uneven shape is formed on asurface of said transport regulating guide which is adjacent to saidfeed roller.
 19. An image reading apparatus comprising: a first readingtransport path having a predetermined inclination with respect to ahorizontal plane and for guiding a sheet downwardly; a first imagesensor for reading an image on the sheet guided by said first readingtransport path; a second reading transport path for guiding the sheetcontinuously from said first reading transport path, an inclination ofsaid second reading transport path with respect to the horizontal planebeing smaller than that of said first reading transport path; a secondimage sensor for reading an image on the sheet guided by said secondreading transport path; and a delivery roller for delivering the sheetguided by said second reading transport path out of the apparatus in adirection having an inclination smaller than that of said second readingtransport path with respect to the horizontal plane.
 20. An imagereading apparatus according to claim 19, wherein said first image sensorhas first contact glass for guiding the sheet, said second image sensorhas second contact glass for guiding the sheet, and an angle ofinclination of a guide surface of said first contact glass with respectto the horizontal plane is greater than an angle of inclination of aguide surface of said second contact glass with respect to thehorizontal plane.
 21. An image reading apparatus according to claim 20,wherein a pair of delivery rollers nips the sheet therebetween, and anangle of inclination of a common tangent of said pair of deliveryrollers with respect to the horizontal plane is smaller than the angleof inclination of said guide surface of said second contact glass withrespect to the horizontal plane.
 22. An image reading apparatusaccording to claim 19, wherein said first image sensor reads an image ona first side of the sheet, and said second image sensor reads an imageon a second side of the sheet which is opposite to the first side.